/*
*
* Intel Management Engine Interface (Intel MEI) Linux driver
* Copyright (c) 2003-2012, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/pci.h>
#include <linux/sched.h>
#include <linux/watchdog.h>
#include "mei_dev.h"
#include "hw.h"
#include "interface.h"
#include <linux/mei.h>
static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
const u8 mei_wd_state_independence_msg[3][4] = {
{0x05, 0x02, 0x51, 0x10},
{0x05, 0x02, 0x52, 0x10},
{0x07, 0x02, 0x01, 0x10}
};
/*
* AMT Watchdog Device
*/
#define INTEL_AMT_WATCHDOG_ID "INTCAMT"
/* UUIDs for AMT F/W clients */
const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
0x9D, 0xA9, 0x15, 0x14, 0xCB,
0x32, 0xAB);
static void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
{
dev_dbg(&dev->pdev->dev, "wd: set timeout=%d.\n", timeout);
memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE);
memcpy(dev->wd_data + MEI_WD_HDR_SIZE, &timeout, sizeof(u16));
}
/**
* mei_wd_host_init - connect to the watchdog client
*
* @dev: the device structure
* returns -ENENT if wd client cannot be found
* -EIO if write has failed
* 0 on success
*/
int mei_wd_host_init(struct mei_device *dev)
{
mei_cl_init(&dev->wd_cl, dev);
/* look for WD client and connect to it */
dev->wd_cl.state = MEI_FILE_DISCONNECTED;
dev->wd_timeout = MEI_WD_DEFAULT_TIMEOUT;
dev->wd_state = MEI_WD_IDLE;
/* find ME WD client */
mei_me_cl_update_filext(dev, &dev->wd_cl,
&mei_wd_guid, MEI_WD_HOST_CLIENT_ID);
dev_dbg(&dev->pdev->dev, "wd: check client\n");
if (MEI_FILE_CONNECTING != dev->wd_cl.state) {
dev_info(&dev->pdev->dev, "wd: failed to find the client\n");
return -ENOENT;
}
if (mei_connect(dev, &dev->wd_cl)) {
dev_err(&dev->pdev->dev, "wd: failed to connect to the client\n");
dev->wd_cl.state = MEI_FILE_DISCONNECTED;
dev->wd_cl.host_client_id = 0;
return -EIO;
}
dev->wd_cl.timer_count = CONNECT_TIMEOUT;
return 0;
}
/**
* mei_wd_send - sends watch dog message to fw.
*
* @dev: the device structure
*
* returns 0 if success,
* -EIO when message send fails
* -EINVAL when invalid message is to be sent
*/
int mei_wd_send(struct mei_device *dev)
{
struct mei_msg_hdr *mei_hdr;
mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
mei_hdr->host_addr = dev->wd_cl.host_client_id;
mei_hdr->me_addr = dev->wd_cl.me_client_id;
mei_hdr->msg_complete = 1;
mei_hdr->reserved = 0;
if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE))
mei_hdr->length = MEI_WD_START_MSG_SIZE;
else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_HDR_SIZE))
mei_hdr->length = MEI_WD_STOP_MSG_SIZE;
else
return -EINVAL;
return mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length);
}
/**
* mei_wd_stop - sends watchdog stop message to fw.
*
* @dev: the device structure
* @preserve: indicate if to keep the timeout value
*
* returns 0 if success,
* -EIO when message send fails
* -EINVAL when invalid message is to be sent
*/
int mei_wd_stop(struct mei_device *dev)
{
int ret;
if (dev->wd_cl.state != MEI_FILE_CONNECTED ||
dev->wd_state != MEI_WD_RUNNING)
return 0;
memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_STOP_MSG_SIZE);
dev->wd_state = MEI_WD_STOPPING;
ret = mei_flow_ctrl_creds(dev, &dev->wd_cl);
if (ret < 0)
goto out;
if (ret && dev->mei_host_buffer_is_empty) {
ret = 0;
dev->mei_host_buffer_is_empty = false;
if (!mei_wd_send(dev)) {
ret = mei_flow_ctrl_reduce(dev, &dev->wd_cl);
if (ret)
goto out;
} else {
dev_err(&dev->pdev->dev, "wd: send stop failed\n");
}
dev->wd_pending = false;
} else {
dev->wd_pending = true;
}
mutex_unlock(&dev->device_lock);
ret = wait_event_interruptible_timeout(dev->wait_stop_wd,
dev->wd_state == MEI_WD_IDLE,
msecs_to_jiffies(MEI_WD_STOP_TIMEOUT));
mutex_lock(&dev->device_lock);
if (dev->wd_state == MEI_WD_IDLE) {
dev_dbg(&dev->pdev->dev, "wd: stop completed ret=%d.\n", ret);
ret = 0;
} else {
if (!ret)
ret = -ETIMEDOUT;
dev_warn(&dev->pdev->dev,
"wd: stop failed to complete ret=%d.\n", ret);
}
out:
return ret;
}
/*
* mei_wd_ops_start - wd start command from the watchdog core.
*
* @wd_dev - watchdog device struct
*
* returns 0 if success, negative errno code for failure
*/
static int mei_wd_ops_start(struct watchdog_device *wd_dev)
{
int err = -ENODEV;
struct mei_device *dev;
dev = watchdog_get_drvdata(wd_dev);
if (!dev)
return -ENODEV;
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED) {
dev_dbg(&dev->pdev->dev,
"wd: dev_state != MEI_DEV_ENABLED dev_state = %s\n",
mei_dev_state_str(dev->dev_state));
goto end_unlock;
}
if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
dev_dbg(&dev->pdev->dev,
"MEI Driver is not connected to Watchdog Client\n");
goto end_unlock;
}
mei_wd_set_start_timeout(dev, dev->wd_timeout);
err = 0;
end_unlock:
mutex_unlock(&dev->device_lock);
return err;
}
/*
* mei_wd_ops_stop - wd stop command from the watchdog core.
*
* @wd_dev - watchdog device struct
*
* returns 0 if success, negative errno code for failure
*/
static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
{
struct mei_device *dev;
dev = watchdog_get_drvdata(wd_dev);
if (!dev)
return -ENODEV;
mutex_lock(&dev->device_lock);
mei_wd_stop(dev);
mutex_unlock(&dev->device_lock);
return 0;
}
/*
* mei_wd_ops_ping - wd ping command from the watchdog core.
*
* @wd_dev - watchdog device struct
*
* returns 0 if success, negative errno code for failure
*/
static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
{
int ret = 0;
struct mei_device *dev;
dev = watchdog_get_drvdata(wd_dev);
if (!dev)
return -ENODEV;
mutex_lock(&dev->device_lock);
if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
dev_err(&dev->pdev->dev, "wd: not connected.\n");
ret = -ENODEV;
goto end;
}
dev->wd_state = MEI_WD_RUNNING;
/* Check if we can send the ping to HW*/
if (dev->mei_host_buffer_is_empty &&
mei_flow_ctrl_creds(dev, &dev->wd_cl) > 0) {
dev->mei_host_buffer_is_empty = false;
dev_dbg(&dev->pdev->dev, "wd: sending ping\n");
if (mei_wd_send(dev)) {
dev_err(&dev->pdev->dev, "wd: send failed.\n");
ret = -EIO;
goto end;
}
if (mei_flow_ctrl_reduce(dev, &dev->wd_cl)) {
dev_err(&dev->pdev->dev,
"wd: mei_flow_ctrl_reduce() failed.\n");
ret = -EIO;
goto end;
}
} else {
dev->wd_pending = true;
}
end:
mutex_unlock(&dev->device_lock);
return ret;
}
/*
* mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
*
* @wd_dev - watchdog device struct
* @timeout - timeout value to set
*
* returns 0 if success, negative errno code for failure
*/
static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev, unsigned int timeout)
{
struct mei_device *dev;
dev = watchdog_get_drvdata(wd_dev);
if (!dev)
return -ENODEV;
/* Check Timeout value */
if (timeout < MEI_WD_MIN_TIMEOUT || timeout > MEI_WD_MAX_TIMEOUT)
return -EINVAL;
mutex_lock(&dev->device_lock);
dev->wd_timeout = timeout;
wd_dev->timeout = timeout;
mei_wd_set_start_timeout(dev, dev->wd_timeout);
mutex_unlock(&dev->device_lock);
return 0;
}
/*
* Watchdog Device structs
*/
static const struct watchdog_ops wd_ops = {
.owner = THIS_MODULE,
.start = mei_wd_ops_start,
.stop = mei_wd_ops_stop,
.ping = mei_wd_ops_ping,
.set_timeout = mei_wd_ops_set_timeout,
};
static const struct watchdog_info wd_info = {
.identity = INTEL_AMT_WATCHDOG_ID,
.options = WDIOF_KEEPALIVEPING |
WDIOF_SETTIMEOUT |
WDIOF_ALARMONLY,
};
static struct watchdog_device amt_wd_dev = {
.info = &wd_info,
.ops = &wd_ops,
.timeout = MEI_WD_DEFAULT_TIMEOUT,
.min_timeout = MEI_WD_MIN_TIMEOUT,
.max_timeout = MEI_WD_MAX_TIMEOUT,
};
void mei_watchdog_register(struct mei_device *dev)
{
if (watchdog_register_device(&amt_wd_dev)) {
dev_err(&dev->pdev->dev,
"wd: unable to register watchdog device.\n");
dev->wd_interface_reg = false;
return;
}
dev_dbg(&dev->pdev->dev,
"wd: successfully register watchdog interface.\n");
dev->wd_interface_reg = true;
watchdog_set_drvdata(&amt_wd_dev, dev);
}
void mei_watchdog_unregister(struct mei_device *dev)
{
if (!dev->wd_interface_reg)
return;
watchdog_set_drvdata(&amt_wd_dev, NULL);
watchdog_unregister_device(&amt_wd_dev);
dev->wd_interface_reg = false;
}
